1. Field of the Invention
The present invention relates to a method for press molding a thermoplastic resin. More particularly, it relates to a method for producing a multi-layer molded article comprising a molded thermoplastic resin body having a plurality of ribs and/or bosses and a layer cf a foam on the side of the molded thermoplastic resin body having the ribs and/or bosses. Such article is usually used as a heat insulator and the like.
2. Description of Prior Art
Conventionally, a multi-layer molded article of FIGS. 1 and 2 is produced by molding a thermoplastic resin body 1 having the ribs 2 and/or bosses 3 by, for example, injection molding and then supplying a foamable material such as urethane with a suitable tool followed by foaming of the material. However, this method requires the suitable tools, involves a number of steps, and is expensive.
Instead of supplying foamable urethane, foam body parts corresponding to the ribs and/or bosses which are cut out may be laminated on the molded thermoplastic resin body. However, when the ribs and/or bosses have complicated shapes or patterns, processability is considerably deteriorated.
Another practically employed method comprises supplying a foam having a suitable shape in a mold and supplying a plasticized melt thermoplastic resin in the mold to integrate the foam with the thermoplastic resin body. It is possible to shape an article of the thermoplastic resin having a layer of the foam by supplying the foam parts of which corresponding parts to the ribs and/or bosses are cut out when the foam is laminated on the side of the thermoplastic resin body having the ribs and/or bosses. However, this method still has some disadvantages such that the resin material protrudes on the opposite side at the cut out parts.